Mineral oil is one of the most basic and commonly used ingredients in cosmetics. It is used for a variety of purposes including imparting specific textural and aesthetic qualities to cosmetic products. Illustrative of these qualities imparted to cosmetics by mineral oil are slip, emolliency, viscosity changes, residual feel and variations in rate of adsorption. Additionally, mineral oil is a solvent for many of the raw materials used in cosmetics. Mineral oil finds application in all forms of cosmetic products such as creams, lotions, cleansing creams, night creams or lotions, moisturizing creams or lotions, shaving products, make-up products, e.g., lipstick, rouges, etc.
The type of emollient products in which mineral oil is used are described as having various "feels" such as slip, drag, tack, lack of tack, etc. While the feel of a particular emollient will depend an the overall formulation, the mineral oil is an important contributing component to give the emollient the desired properties. Although there has been a recent resurgence of the use of natural oils in cosmetics, this has been primarily limited to the health oriented market. Since the turn of the century, mineral oil has dominated the market for oils used in toiletries and cosmetics because it is odorless, water white, chemically inert and relatively inexpensive.
There has been some recent concern over the health aspects of the use of mineral oil on the skin. Health oriented magazines such as Prevention (Rodale Press) have featured articles concerning the hazards in its use. Whether the hazards involved in the use of mineral oil in toiletries and cosmetics is a legitimate concern is open to question. However, the perceived hazard has generated a demand for a mineral oil substitute for these uses, especially in those products which are advertised as containing natural ingredients.
Heretofore the need has gone unfulfilled. Substitutes offered to the trade have lacked some important characteristic generally attributed to mineral oil such as emolliency, slip, cushion, rate of adsorption, penetration, etc. Since the viscosity of the mineral oil has an effect on the overall characteristics of the product in which it is used, it is preferred to match oil viscosity in any substitute product. The mineral oils currently used in toiletry and cosmetic products have a viscosity range of about 70 S.S.U. to about 350 S.S.U. at 100.degree. F.
The lack of success in developing a substitute for mineral oil has been in part because compounds, other than mineral oil, approved for use in the cosmetics trade are either of too low viscosity to allow them to match mineral oil properties, or where they have high viscosities they have a tacky or gummy feel.